Maximum and minimum length control for a rolling mill shear



Feb. 23, 1965 B. R. NEE| Y, JR 3,170,355

MAXIMUM AND MINIMUM LENGTH CONTROL FOR A ROLLING MILL SHEAR Ifji INVENTOR. Benjamin R. neely 3.7:

BY mlm @Mob HI lo'rneys Feb. 23, 1965 I B. R. NEELY, JR 3,170,355

MAXIMUM AND MINIMUM LENGTH CONTROL FOR A ROLLING MILL SHEAR Filed Sept. l, 1961 3 Sheets- Sheet 2 swamrlzl FLAG CR /u L. ZICR [8a- TR L "43 44\|=| 'TIR l' 45/" BCR cAuBRArloN FLAG BCR II/ Il I\ Aux CTR 45g 3\ az: H :NI :79 R T slclRk lv l l N k 'U\ 64M o a 2v a: '1a ,H

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Ls. 49/" I. "`5l l l ll/ I i l 5 HAND cuT 40553 54 g i l/ujla INVENTOR Benjamin R. Neely )at BY w, @um NW H t terne' y's' Feb. 23, 1965 B. R. NEELY, JR 3,170,355

MAXIMUM AND MINIMUM LENGTH CONTROL FOR A ROLLING MILL SHEAR INVENTOR. Benjamin R. Neely 9a:

Y E. im MM HZZoTneIl/s .er Q.

limited .States 'Patent 3,17%,355 MAXIMUM AND MINIMUM LENGTH CNTRL FR A RQLLING MILL SHEAR lieniamin R. Neely, Jr., West Boylston, Mass., assigner to Morgan Construction Company, Worcester, Mass., a corporation of Massachusetts Filed Sept. 1,1961, Ser. No. 136,405 Claims. (Cl. 33-362) This invention relates generally to apparatus for cutting individual lengths of material from a continuous supply and more particularly to an apparatus and method for regulating and controlling the operation of the shear to obtain lengths of the material greater than a predetermined minimum length. Y

There are many processes in industry which require the cutting of individual lengths of product from a continuous supply of material of indeterminable length and Weight. ln the steelindustry it is a common practice to supply a billet of indeterminate length and weight to a plurality of sequential rolling stands to provide an elongated end product which is subsequently sheared into individual pieces kof equal length to facilitate handling and for further processing. Since billets vary somewhat inlength, cutting the rolled product produced from the billets generally results in a remainder section having a lesser length than the previous cut lengths. It this remainder section is of only slightly shorter size than the 'other sect-ions it can usually be handled with little or no complications during subsequent operations; When the remainder section is below a predetermined minimum length diliculties are experienced with vthe short length f whichintenferes with the handling apparatus for the product, resulting in obstructions and eventual shut-down of the operation.

e This problem is present in the steelindustry in rolling millioperations -where multiple lengths of elongated rod are` sheared and transferred, to cooling beds. 4Inthe transferring operation to the coolingbed. after shearing, e a time delay is necessaryto provide` a gap between the butt end of one bar and the entrance of thelead end of a subsequent-bar. This gap is ynormally provided byhaving rollersfon a run-oit table running approximately V10% faster than the( rollers near the mill end to accelerate the cut length. In order tocreate suticient gap, the product remaining onthe slow-speed section'of the table must Vnot Y be less than 'a specific minimum length for a given mill speed. Otherwise, a short remainderwould accelerate to high speed before the necessaryvgap between the lengths hadrbeen created. Naturally, the .minimum length required to produce the necessary gap increases Vas` mill speedincreases. Aftera bar is transferred'by the kick-V and apparatus for shearing lengths from an elongated product which may be handled efficiently by a cooling bed.

These and other objects will be apparent from the following detailed description taken in conjunction With the accompanying drawings in which:

FlGfl is a schematic plan view of a rolling mill operation embodying the invention; and

FIGS. 2a and 2b are a schematic wiring diagram of a control system in accordance with the invention.

The present invention will be described as applied to a rolling mill 1t) in which heated billets 11 are supplied from a furnace 12 to a series of reductionstands 13 in which the cross-sectional area of the billet is successively reduced. As many stands are provided as required by the work involved and each succeeding stand operates at a somewhat increased linear speed due to the lengthening effect of the reduction in the stands lwith the resultant increasein speed as the cross-sectional area of the product moving through the mill becomes smaller. The path of the product passing through the stands 13 includes a survey dag 14 which may be any conventional device to l i actuate a switch closure or produce otherfconventional electrical signal output on line 15 when material is passing the position ot the flag 14.- l

The path of travel of the billet continues beyond the survey flag 1li through additional reduction stands 13 and ultimately reaches'a shear 16 which is operated by an p ag 19 which also provides an electrical signal such as a switch actuation. The calibrationag 19 is located onf the line a known distance from the' shear 16 in order to provide a calibration in terms of counts which will be equivalent to the, linear length of the product between Athe shear 'iiag and the calibration flag as will hereinafter appear. Beyond the calibration ilag 19 the severed lengths or" the bar produced by .the mill are delivered to a cooling bed orother suitable receptacle forthe lengths. Y

`The control of the mill in accordance with'the present invention is obtained by means of a survey counter 21, a

master counter 22 and an auxiliary counter 23, Vthe latter counter being for initial calibration only. AThe control of these counters is indicated only generally in FIG. l, the

off from the table rollers tothe rst` notch of the cooling l bed, the vbar slides to a stop and is vthen advancedone notch byV thev carryoverl "Several seconds l are required for alban to 'slide toy astop and to vbe,4 advanced by ther 1 carry-over. f The time required forrthis operation increases as the millfspeed increases. This means that for higher. .mill speed longer lengths must-be cut in order thatA each lengthma-ybeindividually carried across the cooling-bed..V f ,A111 objectof theinvent'ion is to provide for selectively shearing Van alternatelylengthofl product to assurethat all lengths sheared from arandom size billet willbe longer than 'a kpredetermined minimum. Another object of this invention. to provide vmethod fand apparatus for `ascertaining `whether a' remainder ,section resulting 1f rom a multiple cutting operationV will -bebove or 'below a,.-

' of the shearfla'g 18.- The calibration flag 19` supplies arg1 switchactuationforcontrolling the auxiliary counter .23.;- beany suitable device for` lcou-nting electrical lin ipulsesV vapplied thereto online-10 Y ."and capable of being reset electrically/gto. zero. when a ysuitable reset signal' isV applied'thereto. Thisfresetpis Y predetermined minimum length prior lintime to the nalf shear *operation` so Ias to allowan alternate cut length l foroneof the niultiplecutsfthereby 'assuring a remainder s ,begisdiefna'i` by .Suitable aiaipiadicatorsjassnd e ,Y

cperationct Athecounter 2; iS'f Silhfha 2l SWilCh l .uz Y.

actual details of the circuittarrangement beingdescribed herein with reference to FIGS. 2a and 2b.., In the arrangef Vment of.-FlG. l, the survey counter is shown to be co n-V 'trolled by the output oniline 1S from thefsurvey flag 14 y Vwhile the master counter 22 ris controlled by the outpntV j ,The survey .counterV 21 may accomplishedwithout vlosing any counts thatV appear at ,the-input vline 10. Thesurvey counter 21 isfequipped Vwith two preset controls Zjandf by'which preset counts 4 "can beestablished in thecounter by manually adjusting the controls; 24 and v25. The numericalfvalue .oflvthe l `count.establishedl by the 'respective controls 2j4,2l'e`lmay V Y v TheV Patented Feb. 273, 1965 Y KJ ation is available when the .count accumulated in the counter equals one of the preset counts set by the control 24 or 25.

, The master counter 22 may be a device similar'to the survey counter 21 and capable of accumulating counts in response to electrical impulses on line 1u and switch closures received from the shear flag 1S. The counter 22 has two preset controls 31 and 32 and a reset control 33, by which preset counts can be established. Dial indicators 34, 3S and 36 may be provided by indicating the preset counts established in the counter 22. The characteristics of the master counter 22 provide switch actuations upon the count accumulated in the counter corresponding to the number of the preset count established by the controls 31 and 32. The counter 22 is capable of being reset to zero by an electrical input or reset to the preset count established by the setting of control 33. For the latter condition counting starts at the preset value set on dial 36 instead of starting from zero.

The auxiliary counter 23 operates in response to electrical signals from the line andthe calibration ag 19 to accumulate counts during an interval related to actuation of the calibration flag 19.

In each instance, the counters 21, 22 and 23 are actuated by the above described inputs fromthe various flag controls to count impulses obtained from a pulse generator 23 which operates from a nal finishing stand 29 to provide an electrical signal bearing a predetermined relation to the linear speed of the product through the stand 29. For convenience of operation the electrical pulse output of the generator 2S is arranged to be one pulse per linear foot of travel of the product through the stand 29. This pulse rate is applied to each of the counters 21, 22 and 23 so that the counts accumulated in the respective counters represent feet of travel of the product through the nal finishing stand 29.

Referring now to FIGS. 2a and 2b assembled as indicated, a description of a complete circuit of a preferred embodiment of the control systemv of the invention will be described. p The circuit comprises a number of branches connected between electrical power lines 41 and 42. The circuits connected between the power supply lines 41 and 42 will be described brieily for identification with their operation to control the system in accordance with the invention'set forth hereinafter. shear ag 1S has a normally open contact 18a serially connected with a control relay ZCR betweenthe lines 41 and 42. The contact 18a is open whenever there is no product passing beneath the shear flag 18. Consequently, when there is product present -in the position of the shear flag 18, contact 18a is closed and relay ZCR is energized. A set of normally closed contacts 43 actuated by the relay ZCR is serially connected to energize a time delay relay TR whenever the relay ZCR is not Y energized. A relay 3CR is connected between line 42 and line 41 to be energized through one of two paths, a normally open contact 44 ofrelay 2CR and a normally open contact 45 of relay TR. TheV operation of the timing relay TR is such that once it is energized thereon- Vtacts 45 will remain lclosed for a short interval after ythe Vrelay TR is de-energized. The second actuating circult for the Vrelay SCR is through normally closed contacts 46 actuated by the calibration ag 19 in series with normallyV open contacts 47 of relay SCR. The contacts 46 are closed except during the passage of the product past` the location of the calibration ag 19. 'Y s A relay 4CRv is energized through any one of four different control circuits as follows. A set of normally open contacts .4S on the master counter high preset is The energizing circuit for the relay yICR is through a normally closed contact 52 which is a switch associated with the shear and designated a'limit switch. The limit switch 52 is actuated every time the shear actuates to shear the bar of other product passing the shear 16. The contact 52 is in series with a normally open'contact 53 which is operated by the relay 4CR. The fourth circuit for energizing the relay 4CR is a manually actuated switch 54 arranged to energize the relay SCR for hand cutting of the bar.

A relay SCR is arranged to be energized by contact 55 actuated bythe survey ag 14. Whenever stock is passing the survey flag 14 and present thereunder the contacts S5 are closed to energize the relay SCR.

A relay 6CR is energized by two alternate circuits, one of which connects the relay 6CR across the lines 41 and 42 through normally open contact 56 associated with the survey counter high preset. The contact 56 closes whenever the survey counter reaches the high preset and this closing is of a momentary nature. The second circuit for energizing the relay 6CR is through normally closed contact 57 actuated by the survey counter low preset and normally open contact 5S actuated by the relay 6CR.

A relay 7CR is energized by two alternate paths one of which includes a normallyl closed contact `59 loperated by the relay SCR in series with normally open contacts closedv contact 63 actuated by the master counter low preset.

The shear 16 is operated by a shear solenoid 64 which y is energized through normally open Contact 65 of the relay 4CR. Thus, energization of the relay 4CR operates the shear solenoid to cut the bar passing the shear position.

The survey counter 21 is supplied counting pulses from lines 66 which are energized from the pulse generator tachometer 28. length of product passing the she-ar 16 are supplied to the survey counter 21 through normally open contacts 67 of the relay SCR. Since the relay SCR is energized by the survey flag contacts 55, the survey counter 21 will count pulses from the line 66 whenever a product is passing the survey flag to close the contacts 55. A set of reset terminals 68 is provided on the survey counter 21 which resets the survey counter to zero whenever the contacts 68 are shorted.- Two circuits are provided for shorting the contacts '68, one through a normally closed contact 69 actuated by the relay SCR and another circuit through a normally open contact 71 actuated by-the survey counter high preset. Thus the ksurvey counter- 21 will be reset whenever either the relay ECR is vie-energized indicating that no product is present at the survey flag 14 or whenever the surveycounter 21 passes a value of the high preset -in its counting sequence.

The master counter 22 counts pulses from'the line 66 whenever arnormallyopen contact 72 is closed; 'Thecontact 72' is actuatedv by the relay ZCR.r VSincev the relay ZCR is energized whenever the shear Hag contact 18a iS closed, indicating that there'isproduct present at the Vshear 16, the master counter 22pcounts'during the intervals when `the product isI present at the shear 16. A seto'f terkm'inals 73"'onithe-master counter 22 provides for resetting the mastercounter to zero whenever the terminals 73 are shorted. A circuit for shorting theterminals 73 isl provided through normally open contact Y74 actuated by the connected'to energize Vthe relay 4CR. A second 'circuit for energizing' the relay 4CR isthrough a set ofnorf mallyfopen contacts 49 which are actuated by the master counter lo\v"preset`in series with normally open conrelay 4CR and in'series with normally'` open contact 75 actuated by the lrelay ZCR. Thus the master counter is resetto zero only when both relays ZCR and 4CR are v energized simultaneously. This reset of the master Acounter" 22 toz'er'o thsoccurswhenever a cut is'made by Y th'sne'aifl Afsecondset ofp'r'e'set terminals 76 is provided `on the master counter 22 to Areset :the counttoa These pulses representing thc` s'hear delay preset value. The terminals 76 are shortcircuited through a normally closed contact 77 operated by the relay ZCR. Thecontact 77 is thus open whenever the product is present at the shear ag resulting in the energization of the relay ZCR and hence the reset of the counter 22 to the shear delay preset value occurs only at the end of a bar when the shear ag is released by the absence of material at the shear.

The auxiliary counter Z3 receives counting pulses from the* line 66 through two alternate circuits which are selectable by a selector vswitch having contacts 7 8 and 79 ganged to be in opposite conductivitycondition. For the setting of the selector switch shown in FIG'. 2a, the closed contact 78 supplies counting pulses through a normally open contact 81 actuated by a relay SCR to the auxiliary counter 23. For the opposite setting of the selector switch the contact 79 would be closed and contact 78 open for which condition a normally open contact 82 operated by the relay 4CR would supply counting pulses to the auxiliary counter 23. .The auxiliary counter 23 has a zero reset circuit 83, operated by a manually actuated reset switch 84.

The operation of the system of the invention will now be described.. As a billet travels through the mill the headend reaches the survey flag 14 closingV contacts 55 and picking up the relay SCR; This Vcloses the contact 67 and the survey counter 21 starts counting pulses which are a measure of the distance the final product travels as determined by the pulse rate of the tachometer 28 at'the final stand 29. `The su'rvey counter 21 continues to count until itreaches a countcorrespondingtoits own high presetting the survey counter 21 to zero and the contact 56 als'oJcloses energizing the relay-` 6CR. vThe relay 6CR remains energizedthrough a holding contact 5S andthe normally closed survey counter low preset contact 57. When the survey counter low preset count is reached, the contact 57open'sand the 4relay 6CR is 4cle-energized. Thus, the relay 6CR islnormally picked-up for each length off the bar countedV corresponding to the setting of the survey counter'` high preset. The head of the barproceeds through the mill for a multiple number of lengths of th'e bar lengtht'to be. cut `and inally reaches the shear ag 18'. The multiple Vnumber oflengths between the survey flag 14 and'theshearilag 18,; is assuredvby the selection of the location ofthe survey flag.` The Ahead of the bar appearing atthe shearag 18 closes the contact 18a to pick-up the relay 2CR which closes the contact172 to start the master counter counting. v When the master counter reaches its high preset count the switch contact 48 closes'momentarily energizing the relay ACRwhichfseals in through the circuitprovided by the'normally Vclosed contact of the r shear limit switch 52 and the holding contact 53 of the relay 4CR. With Vtheur'elay 4CR 'pickedfupthe contactos closesto venergize Vthe shear solenoidrsfiandmake a cut in` the bar ,thatis yunder the shear. "Since both relays `ZICR switch opens to jlet the'relay 4CR`dr-op out. f v

. set at which time the 4contact 71 closes momentarily re-vy i reaches its low preset value.

6, picked-up due to the previous momentary closure of the high preset contact 56 and the holding circuit through contact 58 and contact 57. The relay 6CR remains energized for condition (2) since the passage of the tail of the billet from under the survey tlag opening contact 55 deenergizes the relay SCR and stops the survey counter 21 from counting, thus the holding circuit through the contacts 57 and 58 is not broken since the survey counter does not reach its'low preset to open the contact 57. With the relay GCR energized and the relay SCR de-energized, a circuit is made through the contacts 59 and 61 to energize the relay 7CR. This circuit is held through a holding circuit provided by the contact 62 and the master counterlow preset contacts 63 which are normally closed. In this fashion, the energization of the relay 6CR is no-t affected by the emergence of a subsequent billet and the beginning of counting in the survey counter 21Has soon as the lhead of that billet appears at the survey ag 14. With the relay 7CR picked-up, thecontact 51 is closed to provide an energizing circuit for the relay 4CR as soon as the master counter reaches its low preset count and closes switch contact 49. Thus the detection of the tail of the billet when the survey counter 21 has not reached its low preset count results in a cut being made by energizing the relay 4CR the next time the master counter This alternate length of cut is established by the master counter low preset to be of such length as to make all of the lengths cut by the mill above a predetermined' minimum for convenience Vand economy of handling in subsequent operations.

The operation of the `counters to insure all cut lengths greater than a predetermined minimum is as follows. Assume that'it is desired to have anormallength cut of 185 v 4feet and that the minimum length desired is 75 feet.V Then .the high preset for both the master counter'andthe survey counter will be set for .the countcorresponding to l185 feetand the 'lowpreset of the survey counter is set to av count corresponding to the minimum length preset which may be, for example, 75 feet.` The low preset ofthe master counter is set to the alternate' length of cut preset value which maybe, for example, 100 feet.y For these settings if the tail end of the product releases the'survey flag 14 when the count in the survey counter 21- is "above the min;- imum length preset, the master counter willv continue to4 operate Without change to cut 1engths`of`185 feet as determinedby its high preset count with the remainder being somewherebetween 75 and 185 feet in length as pre viously detected by the survey counter.

. of the billet releases the survey flag 14 when the survey reached its low pre set-value,the.cycle of the master y counter is modified as;hereinafter'described.

*Forstheeonditiori(1)' above the passage of the tailof the billet'past thesurvey "ilag 14 opens lthe contact Y55 dropping. out thehrelay.I SCR ,and .terminating the count in the surveyjcounter 21 by; openingtthe contact' 67p; Thisr action` closesthe Contact 69 toreset theV survey 'countery 1.

` 21to'zerojpreparatory-tothe arrival of the nextbilletg ',Q y For-,condition .1(2) above the relay 6CR willbealready count is less than the minimum length preset, i.e`.'V some- `where between zero and feet,V the master counter`f22 the next time it reaches the alternatelength of cut preset* which in the present example is'v 100 feet,lwillenergize the f shear to cut a `100 foot length of bar. After this cut the master counter will resume cuttingthe desiredl foot lengths until the last piece come's'through theshear andv`r4 due tothe actionofY the alternate length of cutfpreset, thev remainder, `in .this case, willV be .185-l-20fl00f:v 105 feet.

The value of-20 in .this equation corresponds tothe count which. was presentat the' survey 'counter when the tailY .of the billet released the survey liag. VAny other. value between zero and 75V vfeet would `.change the length of 1the remainder'but in no eventA would lit be less 'than S55ffeet A and hence the. minimum length. cutwould b'egreater than the 75 foot minimumestablished for-theequipinent in this `fparticular mode of operation.V lTh function ofth'eauxiliary counter 2,3` isi'asifollows.

Y With theV selector switch inthe position shown in FIG. 2a 'l with contact 78 closed and contact79` opened the auxf` lf the tail endV closed momentarily after the contact 43 opens. The auxiliary counter 23 thus counts until the head of the bar reaches the calibration ag 19 since a holding circuit is provided through the holding contact 47 and the normally closed contact 46 of the calibration iiag. When the head of the bar reaches the calibration liag 19 the contact 46 opens, de-energizing the relay SCR and stopping the count in the auxiliary counter Z3. By adjusting the distance between the shear dag i8 and the calibration flag 19 to the known length, the calibration of the counting pulse rate in terms of counts per unit length can be achieved and used to modify the settings of the various counters in the event that a one-to-one relation between counting pulses and units of length is not feasible in the system. The operator may then manually reset the auxiliary counter 23 with the switch 84 after he has read the counts on the auxiliary counter to obtain a calibration of the system in terms of counts per unit length.

For a setting of the selector switch opposite to that shown in FIG. 2a the contact 79 would be closed and the contact 'I8 open. In this position the auxiliary counter 23 measures the count delay corresponding to the time interval between when the shear signal is applied electrically and the time that the actual cut is made. For this purpose the shear signal resulting from the energization of the.

relay 4CR closes the contact 82 thereby starting the count in the auxiliary counter 23. This count is started without any product passing through the mill and a cut is simulated by closing the manual hand cut switch 54 to energize the relay dCR. The relay CR is deenergized by thelopening of the contact 52 of' the shear limit switch and the count accumulated in the auxiliary counter 23 during this interval represents the shear delay. This count is then set as the shear delay preset in the, master counter 22y and this is the'value to whichl the master counter is preset whenever the contact 77 is closed correspondingto a de-energized condition for the relay ZCR. Thus each time a new billet head end arrives at the shear to close the contact 18a and energize the relay ZCR, the master counter V22 will start counting from thcrshear delay preset value. be initiated at a time corresponding to the length of the piece to be cut less the distance the product will travel as the shear falls. Accordingly the first cut will be of the proper length even though there is some delay in actuating the shear. As long as the shear flag contact 18a is closed the reset of the master counter 22 is to zero and the delay f compensation is inherently present for all of the pieces subsequently cut from the same billet. piece of that billet drops'k the'shear flag to de-energize the relay ZCR themaster counter 22 is again preset to` the shear delay preset in order to compensate for the shear delay in the next billetl group which is cut.-

From the foregoing description it will be understood that the survey counter 21 and the master counter 22 count pulses from the generator 28 which represents units of length of the finished produjct as it enters `the shear.

Although the vsurvey counter is controlled by the survey flag 14 where the product has a much lower linear speed than the finished product at the shear ag 18, the count accumulatedin thesurvey vcounter 21I for any weight of product passing lthe survey'tfiag 14n/ill be equal to the The first cut which is made will, therefore,l

When the tail` i rangements are feasible for utilizing the teachings of the present invention to achieve prediction of the ultimate length of the final piece being cut from a random size of stock running through the mill. Accordingly such modifications as fall within the scope of the appended claims are to be considered within the vention.

I claim:

l. Apparatus for cutting elongated product into sections as it moves in the direction of its length, comprising a shear lying in the path of movement of the product, a first means for sensing passage of said product in said path upstream from said shear and determining the length of the remainder section of the productv above the largest whole number of sections of predetermined normal length, a second vmeans for controlling the shear to cut the product into the said whole number of sections of predetermined normal length, and a third means operative in response to sensing by said first means of the length of the said remainder section above a predetermined minimum length to allow the shear to cut the product into the said whole number of sections of normal length and operative in response to sensing of the length of the said remainder ection below the said minimum length to cause the shear to cut one of thc sections preceding thc said remainder section to a predetermined intermediate length selected to make the actual remainder section larger than the said minimum length.

2. Apparatus for cutting elongated product into sections as it moves in the direction of its length, comprising a shear lying inthe path of movement of the product, a tachometer generating electrical pulses at a rate indicative of the speed ofthe product at a given position in said path, a tlag indicating at all times the presence or lack of presence of the product at a fixed position in said path, a survey counter which counts pulses from the tachometer only when said flag indicates the presence of the product, said survey counter determining the length relativeV to a predetermined minimum lcngth of the remainder section of the product above the largest whole numberfof sections of predetermined normal length, and meansoperative in responseito detection by said survey counter of the length of the said remainder section above a predetermined minimum length to allow the shear to cut the product into the said whole number of sections of normal length and operative in response to detection of the length of the said remainder section below the said minimum length to cause said shear to cut one of the sections preceding the said remainder section to a predetermined length intermediate of the normal length and ,the minimum lengthelected to make the actual remainder section equal to or longer than the saidminimum length.

3. Apparatus for cutting elongated product into sec- `tions as'it moves in the direction of its length, comprising a shear'lying in the-path of movement of the product, a

Y tachometer generating electrical pulses at a'rate indicative fioV count accumulated in themaster counter for the same 3 i product weight passing (at much higherlinear speed) the shear flag 18. This relation holdsbecause the ratio ofthe length of a'given quantity of steel to its linear speed It will also be noticed that the present inventionV contemplatesmill operation in which there are no growing or shrinking loops between the survey Hagar-4 and the ,shear flaglS. The mill is normally adjustedto achievethis condition on the trial bars used to set up-the mill. l

While a particular specific embodiment ofthe control v (lengthper unit time) at any point in the mill is constant. i

of the speed of the product at a given' position `in said'v path, a flag indicating at all times the'presence or lack of presence of the product at a lixedposition in said path upstream from said shear, agvsilrvey counter which Vcounts pulses from the tachometer only when the tlag indicates the'presenc'e of the product/theV survey counter determining the length ofvthe remainder section of the product above the largestwhole number of sections of predetermined) normal length, a masterfcounter which receives pulses from the tachometer, and'a'minimum length con# trol lfor comparing a pre-Set'predetermined minimum length with the length of said remainder section for renderi' ing the master counter operative if the length Vof the said remainder section is above said predetermined minimum length to allow the shear to lcut the"produc' t into the said whole number of sections of normal length and operatlve` v ifthe-lengt-hof thesaid remainder section lisbelow the said minimum length to cause the shear to cut one of the sections preceding the said remaindersection to a predepurview of the present in- Varr/0,355

termined length intermediate of the normal length and the minimum length, so that the actual remainder section is equal to or longer than the said'minimum length.

4. Apparatus for cutting elongated rolling mill product Vinto sections as it moves in the direction of its length toward a cooling bed, comprising a shear lying in the path of movement of the product between the mill and the bed, a tachometer generating electrical pulses at a rate indicative of the speed of the product at a position Within a mill, a flag upstream from said shear indicating at all times the presence or lack of presence of the product at a xed position in said path in the mill, a survey counter which counts pulses from the tachometer only when said flag indicates the presence of the product, thesurvey counter receiving pulses from the tachometer and determining the length of the remainder section of the product above the largest Whole number of sections of predetermined normal length, a master counter which also' receives pulses from the tachometer, a pre-set control for the survey counter to place the survey counter in a rst condition if the detected length of the said remainder section is above the predetermined minimum length corresponding to the pre-set valve established on said pre-set control and in a second condition if the detected length of the said remainder section is below the said minimum length, the

pre-set control being connected to the master counter and Y' 5.` Apparatus for cutting elongatedy product into seci tions longer than a predetermined minimum length as said product moves inthe direction of its length comprising a shear in the path of movement of said product, means for normally operating said shear t-o sever successive sections of said product to normal length, means for determining at a point on said Vpathk upstream from said shear the length of the remainder section or" said product above the largest Whole number of sections of said normal length produced from a ,discrete quantity of said product, means responsive to detection of the length of said remainder section greater than said minimum length for maintaining normal operation `of said shear and means responsive to detection of the length of said remainder section less than said minimum length for operating said shear to cut at least one shorter-section of said product of length less than said normal length but greater than said minimum length, the excess product length in said remainder section provided by cutting said shorter section being suicient to make said remainder section greater than said minimum length. 1

References Cited in the tile of this patent UNITED STATES PATENTS 1,179,119 Lyon Apr. 11, 1916 1,184,076 Cohn May 23, 1916 2,655,994 Vandenberg Oct. 20, 1953 2,950,640 Camp Aug. 30, 1960 2,958,243 Voster Nov. 1, 1960 2,990,741 Haase et al July 4, 1961 FOREIGN PATENTS v t 812,450 Great Britain Apr. 22, 1959 870,571 Great Britain June 14, 1961 

1. APPARATUS FOR CUTTING ELONGATED PRODUCT INTO SECTIONS AS IT MOVES IN THE DIRECTION OF ITS LENGTH, COMPRISING A SHEAR LYING IN THE PATH OF MOVEMENT OF THE PRODUCT, A FIRST MEANS FOR SENSING PASSAGE OF SAID PRODUCT IN SAID PATH UPSTREAM FROM SAID SHEAR AND DETERMINING THE LENGTH OF THE REMAINDER SECTION OF THE PRODUCT ABOVE THE LARGEST WHOLE NUMBER OF SECTIONS OF PREDETERMINED NORMAL LENGHT, A SECOND MEANS FOR CONTROLLING THE SHEAR TO CUT THE PRODUCT INTO THE SAID WHOLE NUMBER OF SECTIONS OF PREDETERMINED NORMAL LENGTH, AND A THIRD MEANS OPERATIVE IN RESPONSE TO SENSING BY SAID FIRST MEANS OF THE LENGTH OF THE SAID REMAINDER SECTION ABOVE A PREDETERMINED MINIMUM LENGTH TO ALLOW THE SHEAR TO CUT THE PRODUCT INTO THE SAID WHOLE NUMBER OF SECTIONS OF NORMAL LENGTH AND OPERATIVE IN RESPONSE TO SENSING OF THE LENGTH OF SAID REMAINDER SECTION BELOW THE SAID MINIMUM LENGTH TO CAUSE THE SHEAR TO CUT ONE OF THE SECTIONS PRECEDING THE SAID REMAINDER SECTION TO A PREDETERMINED INTERMEDIATE LENGTH SELECTED TO MAKE THE ACTUAL REMAINDER SECTION LARGER THAN THE SAID MINIMUM LENGTH. 